Robbie Williams opened the show with his version of "Let Me Entertain You," which the three musketeers seemed to enjoy—how thrilled does Kate look waving her flag in the air?! Will.i.am and Jessie J followed up with the Black Eyed Peas hit "I Gotta Feeling."

Later on, comedian Lenny Henry and the crowd welcomed the queen—who strutted a gold cocktail dress with Swarovski crystals—to the royal box. She was escorted to her seat by Prince Charles and his wife Camilla.

"As a nation this is our opportunity to thank you and my father for always being there for us, for inspiring us with selfless duty and service and making us proud to be British," Charles said of his mother as he addressed the crowd. "The only sad thing about this evening is that my father could not be here with us because he's unfortunately been taken ill. But ladies and gentlemen, if we all shout loud enough he might just hear us."

Prince Philip was hospitalized earlier today after suffering a bladder infection, but we're almost positive he was partying in spirit.